Conventionally, as shown in, for example, Patent Literature 1, a current detection device for detecting a current value flowing through a conductor by a magnetic detection element is disclosed, and the current detection device includes a magnetic shielding body for providing a magnetic shielding region and the magnetic detection element arranged in the magnetic shielding region. The magnetic shielding body is a pair of magnetic plates having the same dimensions. The conductor is a bus bar having a wide plate shape. The pair of the magnetic plates are opposed to each other in a Y direction in a state where the magnetic plates sandwich both peripheries of the bus bar in a width direction from an outside of the bus bar. The magnetic detection element is arranged at a center portion of the bus bar in the width direction. The bus bar and the magnetic detection element are arranged in parallel along a Z direction, which is perpendicular to the Y direction. The magnetic detection element detects a magnetic flux along a direction (e.g., the Y direction), which is perpendicular to the Z direction.
As described above, in the current detection device described in the Patent Literature 1, the pair of the magnetic plates are aligned in the Y direction. In this case, when an external magnetic flux along the Z direction is applied to the pair of the magnetic bodies, the external magnetic flux is bent by each of the pair of the magnetic bodies so that the magnetic shielding region is formed between the pair of the magnetic bodies. However, when the external magnetic flux along the Y direction is applied to the pair of the magnetic bodies, the external magnetic flux is not bent substantially by each of the pair of the magnetic bodies, and therefore, the magnetic shielding region is not formed between the pair of the magnetic bodies. On the other hand, the magnetic detection element detects the magnetic flux along the direction (e.g., the Y direction), which is perpendicular to the Z direction. Accordingly, when the external magnetic flux along the Y direction is applied, the magnetic detection element detects not only a magnetic flux corresponding to the current flowing through the bus bar but also the external magnetic flux. As a result, the detection accuracy of the current flowing through the bus bar may be reduced.